TRJES SOUTH BBN PLANTKR. 



m my great degree, by rendering phosphates 

 or viLe* mineral soluble. 



Ybe ton of rape-ca&o wag calculated to af- 

 ford as DMfth ammonia and minerals as were 

 mpplied in the artificial minerals and ammo- 

 nia mtai on plot 01 It nho contained, in ad- 

 dition, a large amount of carbonaceous matter. 

 Ife will be seen that the increase of wheat is 

 nearly identical in the two cases,, and it. follows 

 tfeat the cardfrndc&MS'mWtk had no beneficial 

 effect on the wheat crop. This alio is a result 

 exactly in accordance with the Rothainstoad 

 expe-riments. 



Similar results to the above have also been 

 obtained from experiments made on the farm 

 ef the Duke of Bedford, at Woburn, on a soil 

 md subsoil naturally of the poorest possible 

 description. 



It will be recollected that Prof Liebig en- 

 deavored to set aside the exceedingly impor-| 

 taut fact that turnips, which contain only a re- 

 latively small proportion of phosphoric- acid, 

 require in the soil, in an available condition, 

 more of this substance than wheat, the ash of 

 which contains five times as much as that of 

 fcttrnips. We showed that he founded his ob- 

 jections on a single typographical error •, which 

 he might have discovered on the next page 

 We fchall. not again allude to the results of 

 Mr. Lawes, experiments on this point; they 

 are so conclusive that he must be blind indeed 

 who cannot see that thsy explode the idea that 

 we can tell what manure is best adapted to 

 this or that particular crop from an analysis 

 of it* ashe3. Our object in alluding to the 

 matter, is to mention that, in the last Journal 

 if the Royal Agricultural Society, Dr. Au- 

 gustus Voelcker, Professor of Chemistry in 

 Hio Koyal Agricultural College, Cirencester, 

 England, gives an account of some experimen- 

 tal trials made on the farm connected with the 

 College, to ascertain "the comparative value 

 •f different artificial manures for raising a 

 crop of Swedes 1 ' or ruta bagas, the results of 

 which also accord with those obtained by Mr 

 Lawes. We have not room for the details of 

 the experiments, but will quote a few of the 

 remarks of Dr. Voelcker : 



"An extended experience lias proved, in the 

 most positive manner, the specific action of phos- 

 phatic manures, and the decided advantages which 

 result from their application to rootcro-ps." 



" Numerous comparative field experiments have 

 established the superior value of superphosphate 

 of lime as a manure for root craps, and have shown 

 likewise that the greatest fertilizing effect of 

 guano is realized by applying it to a white crop 

 or to grass land." 



"Ammonia does not exhibit the same powerful 

 •Sect on Other crops which it does on the cereal*." 



"Ammonia does not benefit root crops hi an 

 e$ual degree as whits .crops • whereas, phosphatic 



manures exercise a specific action on roots,, which 

 cp..ns(9s thera to swell, and thns to increase the 



crop." 



" Phosphoric acid, applied in a form in which it 

 can bo readily assimilated by the growing plant, 



marc tkttn any other fertilizing constituent benefits 

 root crops." 



" On the whole, we may learn from these experi- 

 ments, that the value of ditFerent artificial ma- 

 nures for a crop of Swedes, and no doubt also for 

 other root crops, principally depends on the 

 amount of phosphoric acid contained in them in 

 a form in which it can be readily assimilated by 

 the plants/' 



The experience of practical farmers also 

 agrees with these experiments, in according 

 to available phosphoric acid a high value as a 

 special manure for turnips. One manufac- 

 turer alone sold, in Great Britain, last year, 

 14,000 tons of superphosphate of lime, to be 

 used as a manure for — what ? For wheat, 

 which contains so much phosphoric acid ? 

 No ; but for turnips, which contain so little. 



To conclude, these results point to no " revolution'* 

 in agriculture; they simply throw light on the 

 rational* of systems of rotation and general (arm 

 management, already adopted by practical agricul- 

 turists. They say underdrain your land, so that 

 :he rain water, as it filters through the soil to the 

 drains, may leave its ammonia for the use of plants. 

 Grow more clover, peas, beans, tares, lupines, tur- 

 nips, and other plants, which will retain all the am- 

 monia brought to them in rain and dews, or obtain- 

 ed from the atmosphere, the soil or manure. In 

 feeding cattle, use that food which, other things 

 being equal, contains most nitrogen, for the excre- 

 ments will be correspondingly rich in ammonia. 

 In short, in everything you do, let it be your aim to 

 conserve as much ammonia -on the farm as possible. 

 In this you cannot go wrong, for there is no mean* 

 of getting ammonia in any considerable quantity 

 but what at the same time affords, more of the 

 mineral elements of plants, in proportion to the 

 wants of wheat, and probably of Indian corn, barley, 

 oats, and other high priced cereals, than it does of 

 ammonia. To illustrate : good Peruvian guano is 

 the most ammoniacal manure in the market; arid 

 yet it ci ntains generally as much phosphoric acid 

 as it does of ammonia; while, according to Mr, 

 Lawes' exp«*rimen ; s, a bushel of wheat removes 

 j from the soil five times as much ammonia as it does 

 I of phosphoric acid. In nearly a'i substances used 

 las manure, the proportion of mineral elements 

 relatively to the wants of the wheat plant isgreat- 

 I ]y in excess of the ammonia which they contain. 

 | We cannot impoverish the sod of minerals, 

 ! therefore, by growing large crops jby the aid of such 

 ! manures as are now in the market, if the straw and 

 | home sources of manure are properly husbanded. 

 { Cut, the reader will ask, U we obtain large crops 

 ) of wheat, corn, &o , by accumulating ammonia in 

 1 the soil by the growth of turnips, peas, clover, &c,. 



